We need some kind of base plate first. I still had this sawn off end of a shelf lying around.  I ordered most of the other components directly from Aliexpress in China. It takes forever for the parts to arrive, but everything is incredibly cheap. We need a motor controller, a very slow running motor and three furniture castors. I bought them locally and together they are the most expensive part in this project. Also a battery holder for eight AA-batteries. 8 times 1,5v results in 12V. In the description I will give you links to the parts.

3 rpm 12v motor (the slower one): € 2,81 https://goo.gl/DyGYjh*

The axle of one of the three furniture castors is drilled out. I’ll put the wheel on the motor for a trial. The motor gets connected to the controller. I first had to figure out what goes where, because everything is labeled in Chinese. in this case the motor connectors are left and the input voltage right.

Ok, It’s running. It’s still pretty fast, though.

In the middle of one narrow side I screw a perforated plate to  the underside of the base plate. With only one screw so it can be rotated.

Now I glue the motor to the perforated plate with plenty of hot glue.

On the other side, the other castors are mounted so that we get a tricycle. The vehicle can be steered by turning the plate with the motor.

Now I attach the individual parts to the base plate.

Because the dolly ran too fast for me, I replaced the motor with a slower one.

Now I have fished two switches out of the grab box. One is to change direction. That must be a double two way switch. The cables from the battery are soldered like an X.

For this purpose, I not only stripped the insulation at the end, but also two centimetres before the end. So I don’t have to extend the cables.

This is how it should look in the end:

A second switch is for turning on and off.

This ist the setup I used to film my intro. I put foam under the tripod to dampen the vibrations.

Surely it would have made sense to place the dolly on a very smooth surface, a glass plate for example.

Now, For really long time-lapses this is still way too fast. The dolly would only have to move a few millimeters every minute. We can do that.

This is where an Arduino comes in. This is an easy to use controller module. We also need a relay module. This one has eight relays. That’s way too much, of course, but I still had it lying around. These things are also incredibly cheap in China, see description. I simply connect pins 6 and 7 of the Arduino to the inputs 1 and 2 of the relay module, ground to ground, and the 5v output of the Arduino goes to VCC on the relay board.

Only a few lines of code are needed for this to work. They are simply uploaded into the Arduino via USB. I set the times directly in the code. But you will need to experiment a little, because the Arduino is not so precise in timing.

It’s winter, and I couldn’t think of anything more exciting than a flowerpot full of snow that I put in my kitchen to melt.

The camera takes a picture every minute. The dolly rolls a little bit between the shots. The photos are then assembled into a film at 30 frames per second. So for every half hour we get a second of video. I observed the flowerpot for seven hours. As a precaution, I have connected both the camera and the dolly to power supplies. And here is the finished video again.

If you are willing to wait a long time for delivery, you can order everything you need for the dolly for about 15 Euros in China. And that already includes shipping. check out the links in the description.